Drill-chuck.



No. 747,017. I PATENTED DEC. 15, 1903. G. A. SVENSSON.

DRILL CHUCK.

APPLICATION FILED JAN. 17, 1903.

N0 MODEL.

2 SHEETS-SHEET 1.

7 i7zverzar amr uwm J3 7 No. 747,017. PATENTED DEC. 15, 1903..

. 0. A. SVENSSON.

DRILL CHUCK.

APPLICATION FILED JAN. 17, 1903.

no MODEL. 2 SHEETS-SHEET z.

J y i 123.67

nrrnn Frames Patented December 15, 1903.

arnr rricn,

OLAES A. SVENSSON, OF BUFFALO, NEW YORK, ASSIGNOR OF ONE-HALF ,TO WILLIAM W. OLIVER, OF BUFFALO, NEW YORK.

DRlLL Cl-lUCK.

SPECIFICATION forming part of Letters Patent No. 74=7,017, dated December 15, 1903. Application filedllannary 17, 1903. Serial No. 139,469. (No model.)

TO ME whom it may concern:

Be it known that I, CLAES A. SVENSSON, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and usefulImprovements in Drill-Chucks, of which the following is a specification.

This invention relates more particularly to drill-chucks comprising a head or body carried by the spindle of the drill-press and having a tapering shell, jaws which are movable lengthwise and radially in the chuck, and a screw-threaded mandrel arranged in a central opening of the head and operating to advance and close the jaws.

The object of my invention is the construction of a simple and compact chuck of this class which can be cheaply manufactured, which permits the easy insertion of a drill or 1 other object, and which reliably grips and acourately centers the same.

In the accompanying drawings, consisting of two sheets, Figure l is a sectional elevation of the chuck. Fig. 2 is a side elevation thereof with the shell removed. Fig. 3 is a cross-section in line 3 3, Fig. 1, with the mandrel removed. Fig. 4 is a cross-section in line t 4;, Fig. 1. Fig. 5 is a sectional elevation of a modified construction of the chuck. Fig. 6 is a side elevation of the same with the shell omitted. Fig. 7 is a sectional elevation of another modification. Figs. 8 and 9 are cross-sections in lines 8 8 and 9 9, Fig. 7.

Similar letters of reference indicate corresponding parts throughout the several views.

A is the head or body of the chuck, having a cylindrical upper or rear portion and a tapering lower or front portion. B is the inclosing shell applied to the head and having corresponding cylindrical and tapering portions, as shown, the shell being removably secured to the head by a screw b or other suitable fastening.

Referring to the construction shown in Figs. 1 to 4, the tapering portion of the head is provided with equidistant longitudinal slots 0, which extend radially from the screw-threaded central opening at of the head to the periphery thereof. These slots receive and guide the movable jaws E, which are preferably three in number and which have the customary beveled backs or outer edges bearing against the tapering innersurface of the shell B, so that the jaws when thrust forwardly are contracted and closed upon the drill or other object placed in the chuck.

The jaws may be held against inward displacement by any suitable means; but I prefer to employ keys or feathers f for this purpose. Each jaw is provided with such a key, and the latter is seated partly in a longitudinal groove formed in one side of the jaw and partly in a corresponding groove formed in the adjacent wall of the slot in which the jaw moves, these grooves being parallel with the beveled backs of the jaws to permit the latter to move in and out freely. In the preferred construction shown in the drawings the keys are held in place by bending their upper ends laterally, as shown at f, and seating the same in an annular or transverse groove g, formed in the head, as shown in Fig. 2.

h indicates longitudinal retracting-springs connected with the jaws, respectively, and arranged in rear of their inner ends. These springs are preferably seated in longitudinal grooves t', arranged in the cylindrical portion of the head A in line with the jaw-slots c and forming continuations of the latter, as shown. The front orlower ends of the springs are suitably attached to the rear ends of the jaws, while their rear ends are connected with the upper portion of the head A by any suitable means. This connection may be cheaply effected by springing a split band j into an annular groovej of the head and looping the upper ends of the springs around this band, as shown inFigs. l, 2, and 3.

K indicates the screw-threaded mandrel, which engages with the axial opening at of the head A and which is adapted to bear against the inner or rear ends of the jaws E forthrusting the same forward when" the chuck is screwed upwardly on the rod or the mandrel is screwed farther into the head. For this purpose the straight inner edges of the jaws project inward sufficiently to bear against the lower end of the mandrel, as shown in Fig. 1.

In the use of the chuck upon insertinga drill or other tool between its jaws and screwing the head A upwardly on the mandrel K the jaws are advanced and closed upon the tool, the springs It being distended more or less by this movement of the jaws. Upon screwing the head A in the opposite direction the jaws recede from the end of the mandrel and are at the same time drawn into the chuck and opened by the contraction of their springs.

As shown in Fig. 1, the retracting-springs are arranged above or in rear of the inner ends of the jaws and substantially in the direction of their longitudinal movement, thus insuring a smooth action of the jaws and permitting the use of a single spring for each jaw without liability of causing binding of the latter. This relative arrangement of the jaws and springs also materially reduces the cost of producing the chuck, inasmuch as each jaw-slot c and the complementary springgroove 1 together form practically a single continuous slot or recess which can be milled in one operation. The arrangement of the springs in rear of the inner ends of the jaws also renders the chuck compact in construction.

The key connection between the jaws and the head A is especially desirable for gripping a tool or other object when the jaws project some distance beyond the end of the shell, the keys preventing tilting of the jaws and insuring a full bearing upon the objectplaced in the chuck, thereby properly centering the same.

If desired,longitudinal compression-sprin gs may be substituted for the tension-springs, such a modified construction being shown in Figs. 5 and 6. In this case each jaw is provided with a longitudinal retracting-stem Z, which extends upwardly from the jaw and carries a compression-spring h. This spring surrounds the stem Z and is interposed between a head or enlargement Z of the stem and an abutmentm, which bridges the groove containing the spring. The stems Z pass loosely through openings in the abutments m, so that when the jaws are advanced and closed the stems slide forwardly in the abutments, compressing the springsin an obvious manner. These abutments are preferably seated in an annular groove g, formed in the head A at the junction of its conical and cylindrical portions, as shown in Fig. 6.

In the modified construction of the chuck shown in Figs. 7, 8, and 9 the head A consists of a cylindrical portion only, which terminates at the junction of the cylindrical and conical portions of the shell B. The head is provided in line withthe jaws E with oblique sockets i, arranged substantially parallel with the direction of movement of the jaws and containing compression-springs h These springs are applied to stems n, which are rigidly secured to the jaws, each spring a head at of the stem. In this modification the stems hold the jaws against inward displacement by reason of their rigid connection with the jaws and the close fit of the stems and the springs 10 in the sockets of the head, as shown in Fig. 7.

It will be observed that in each of the several embodiments of my invention herein shown and described the retracting-springs are arranged above or in rear of the inner ends of the jaws and substantially in the direction of their longitudinal movement and that in each construction the jaws. are reliably held in their proper relative positions when open, thus permitting the ready insertion of the drill and insuring a uniform closure of the jaws and the accurate centering of the drill.

I claim as my invention- 1. In a chuck, the combination of a head or body, a tapering shell surrounding the same and held against movement thereon, jaws capable of moving lengthwise in said shell, springs arranged in rear of the inner ends of the jaws and operating to retract the same, and means for shifting the jaws forwardly, substantially as set forth.

2. Ina chuck, the combination of a head or body provided with longitudinal slots or recesses, a tapering shell surrounding said head, jaws arranged in the front portions of said slots and capable of moving lengthwise and radially therein, longitudinal springs seated in the rear portions of said slots and operating to retract the jaws, and means for shifting the jaws forwardly in said slots, substantially as set forth.

3. In a chuck, the combination of a head or body having a screw-threaded axial opening and comprising a tapering front portion provided with longitudinal slots and a rear portion having longitudinal grooves forming rearward continuations of said slots, a shell surrounding said head and having a corresponding tapering portion, jaws movable lengthwise in said slots, a screw-threaded mandrel arranged in the opening of the head and adapted to bear against the inner ends of the jaws, and spiral springs arranged in said grooves and having their ends connected with the jaws and said head, respectively, substantially as set forth.

4.. In a chuck, the combination of a head or body, a tapering shell surrounding the same, jaws which are movable lengthwise in the shell, means for shifting the jaws forwardly, a band surrounding the head in rear of the jaws, and retracting-springs attached at their front ends to the jaws and at their rear ends to said band, substantially as set forth.

5. In a chuck, the combination of a head or body having an annular groove, a band seated in said groove, a tapering shell surrounding the head, jaws which are movable lengthwise in the shell, means for shifting the jaws forwardly, and longitudinal tension-springs having their front ends attached to the jaws sponding groove, and a key seated in said and their rear ends to said band, snbstancoinciding grooves and having an angular tially as set forth. end seated in said recess, substantially as set 6. In a chuck, thecombination of a body or 'forth. 5 head provided with a longitudinal slot and at Witness my hand this 13th day of Janu- I5 the inner end of said slot with a transverse ary, 1903.

groove or recess, said slot being provided in OLAES A. SVENSSON. one of its Walls with a longitudinal key- Witnesses: groove, a jaw arranged in said slot and pro- CARL F. GEYER,

l0 vided opposite said key-groove with a corre- EMMA M. GRAHAM. 

